Acoustic telephone



(No Model.)

A. ISKE.

I ACOUSTIC TELEPHONE.

Patented July 14,

ihviTEn STATES PATENT OrEicE,

ANTHONY ISKE, OF LANCASTER, PENNSYLVANIA.

ACOUSTIC TELEPHONE.

SPECIFICATION forming part of Letters Patent IIo. 322,291, dated July14, 1885.

(No model.)

To all whom it may concern:

Be it known that I, ANTHONY lsKE, a citizen of the United States,residing at Lancaster, county of Lancaster, and State of Pennsylvania,have invented new and useful Improvements in Acoustic Telephones, ofwhich the folowing is a specification.

This invention relates to that class of telephones which operate withoutmagnets or electrical currents by the propagation of soundwaves in andthrough wires, and which are commonly called acoustic telephones. Inthese telephones it is exceedingly important to keep the wire taut, forthe tighter the wire the more distinctly the sound will be heard. As thewire frequently enters the telephonebox at a very considerable angle tothe surface of the diaphragm, great diiiiculty has been experienced inattaining and maintaining the requisite degree of tightness withoutinjuring the diaphragm, which is preferably of parchment or otherdelicate material.

The chief object of my invention is to avoid this defect and secure therequisite tightness of wire within the telephone-box while leaving thediaphragm free from injurious strain. This object I effect by means ofan anchor or insulator of lead or other material which will not readilyconduct sound, this material be iug connected to the wire and drawn, orarranged in such a way that it will hold the wire taut within the boX,though allowing it to bend at a right angle, yet will not apply anyinjurious strain to the diaphragm.

.In the accompanying drawings, Figure 1 represents a vertical section ofa telephone adapted to receiving as well as transmitting sound-wavespropagated along the wire, said wire being provided with the tensiondevice above referred to. Fig. 2 represents a detail perspective view ofsaid tension device, anchor, or insulator, and Fig. 3 represents adetail view of the receiving-tube and part of the diaphragms.

A designates the telephonebox, having a front, B, in which is formed acentral mouthpiece, C. This last directs the sound-waves, as usual, onthe diaphragm D, preferably of parchment, and the vibrations thus communicated to this diaphragm are transmitted as sound-waves through thewire E.

.ment is used as a transmitter.

The above is the operation when the instru- YVhen it is used as areceiver, the sound -waves pass in the opposite direction along wire Eto said diaphragm and cause the latter to vibrate. The vibrations thuscaused are communicated as sound waves to the air in a sound-chamber, I,formed by the front B,

aforesaid, a partition, G, which is parallel therewith and behind thediaphragm, and interposed walls F at the top, bottom, and sides of thebox A. The front B and diaphragm D are attached to these walls, whichform a base or frame for the diaphragm by screws f, or in any otherconvenient manner. The sounds produced in sound-chamber I by thevibration of diaphragm D pass outward through receiving-tube H toear-piece J. The receiving-tubeis arranged so that its inner end isbisected diametrically by the edge of the diaphragm, so that vibrationsof air on each side of the latter have equal effect, and clear soundsare insured. This receiving-tube is also made rotatable in wall F, inorder that (it being bent or curved in shape) it may present theear-piece .T in the direction where it is needed for use. To effectthis, it is only necessary to turn said tube on its axis.

Whether the instrument be used for transmitting sound or receiving it,the wire E should be held taut within the box A, notwithstanding that itbends in entering said box, and this should be done without greatfriction of the wire against the box or subjecting the diaphragm toinjurious strain. It is manifest that this cannot be effected by a pullon the wire. By means of my anchor or insulator K, I do fully effect it,however. This anchor or insulator, which is tubular, having a centralpassage, is hung to said wire at two points by loops or links 7.), whichcatch under hooks or horns 76 of said weight or anchor K, and islocatedabout midway between the point where the wire E enters the box and thepoint of attachment of said wire to the diaphragm. It is held in placeby a cord or cords L, passing obliquely downward and rearward throughthe central. passage of said tubular insulator or weight, and secured.to the bottom of the box by a screw, Z. By withdrawing this screw andmoving it farther forward or backward before attaching it again, thestrain on the wire may be increased or diminished; but the weight of theanchor or insulator K, which is preferably of lead, will suflice ofitself to apply a considerable degree of tension to the wire, though notenough to hurt the diaphragm. The non-resonant character of the materialof said anchor. or insulator prevents sound waves from being transmittedto or from the wire through this device. It causes the wire to bend soas to pass out of the box nearly at right angles to the course which itfollows between said insulator and the diaphragm, and thus preventsunnecessary friction against the side of' the hole by which said wireenters the box, beside facilitating the keeping the wire perfectly tightand straight outside of the box Having thus described my invention, whatI claim as new, and desire to secure by Letters Patent, is p 1. Thediaphragm, telephone box, and sound'transmitting wire of an acoustictelephone, in combination with a tension device applied obliquely tosaid wire within said box, and cord L and screw Z, for varying saidtension, for the purpose set forth.

2. In combination with a diaphragm wire and box, a receiving-tubearranged with its inner end across the edge of the diaphragm, androtatable to present the ear-piece in any direction desired.

3. A combined receiving and transmitting instrument having a partitionbehind the diaphragm and a receiving-tube located at the edge of thelatter, substantially as set forth.

4. A tension device for a telephone-wire, consisting of a leaden weighthung to said wire, in combination with a cord whereby it is anchored toa fixed device, said weight serving to insulate said wire and also tohold it taut and bent, as described.

5. The tubular leaden anchor K, provided on each side with hooks orhorns, substantially as and for the purpose set forth.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing wit nesses.

ANTHONY ISKE.

lVitn esses:

J AS. 13. DONNELLY, P. DONNELLY.

